Craniofacial adaptations after total maxillary osteotomy in Macaca irus: a cephalometric and histologic study

Area of Science:

• Oral and Maxillofacial Surgery
• Orthodontics
• Temporomandibular Joint Disorders

Background:

• Maxillary impaction is a surgical procedure to correct skeletal discrepancies.
• Understanding the effects on the temporomandibular joint (TMJ) is crucial for patient outcomes.

Purpose of the Study:

• To evaluate cephalometric and histologic changes following total maxillary impaction in Macaca irus monkeys.
• To assess skeletal stability and TMJ alterations after superior repositioning of the maxilla.

Main Methods:

• Five Macaca irus monkeys were utilized, with three undergoing maxillary impaction (5-7 mm).
• Lateral cephalograms were taken over 150 days, with measurements analyzed via superimposition on craniofacial implants.
• Histological examination assessed osseous healing and TMJ structure.

Main Results:

• Excellent skeletal stability was observed post-surgery.
• Normal osseous healing occurred in the osteotomized maxillas.
• Significant TMJ changes included thinning of the temporal fossa's fibrous covering, atrophic condylar cartilage, and thickened articular discs, alongside mandibular overclosure.

Conclusions:

• Superiorly repositioned total maxillary osteotomy demonstrates stability up to 150 days post-operation.
• Significant TMJ alterations necessitate further investigation into neuromuscular responses and adaptive changes.
• Long-term TMJ health and mandibular position require continued study after maxillary surgical procedures.